A drive train is a collective term referring to a plurality of devices for transmitting energy generated in an engine to driving wheels; and the drive train is configured by an engine, a clutch, a transmission, a drive shaft, a propeller shaft, a differential gear, driving wheels, etc. In a performance evaluation test of the drive train, the transmission is actually driven by the engine in a continuous manner, thereby evaluating durability performance, quality, etc. thereof. Recently, as a system for testing such a drive train, it has been proposed that a driving torque to be input into a workpiece is generated by a motor instead of a real engine.
FIG. 7 is a diagram schematically showing a configuration of a drive-train testing system 101. FIG. 7 illustrates an example, of which test piece is a drive train of an FR drive system.
A drive shaft of a motor 103 simulating an engine is connected to an input shaft of a workpiece 102 configuring a part of the drive train. A dynamometer 105 corresponding to a load for absorbing a transmission output of the workpiece 102 is connected to a propeller shaft 104 which is an output shaft of the workpiece 102. The testing system 101 is provided with: a torque meter 106 for detecting a shaft torque acting on the input shaft of the workpiece 102; and a torque meter 107 for detecting a shaft torque acting on the output shaft of the workpiece 102, thereby controlling a driving torque generated by the motor 103, and an absorbing torque generated by the dynamo-meter 105, based on detected values of the meters 106 and 107.
In a real engine, cyclic torque fluctuation is generated due to combustion processes in each cylinder. In the testing system 101 as well, which uses the motor as shown in FIG. 7, it has been proposed that an alternating-current component based on a sine wave is added to a direct-current component for generating a constant driving torque, thereby causing the driving torque generated by the motor to artificially fluctuate, and improving the test reproducibility (for example, see Patent Document 1).
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2002-71520